The proposal is to compare, in children (aged 4-12 years) and adults, the quantitative rules that govern comprehension of synesthetic metaphors, that is, metaphors that combine words or phrases from different sense modalities. By means of psychophysical scaling procedures, the children and adults will judge the meanings of a variety of metaphorical (and nonmetaphorical) combinations of words describing sensory experiences on semantic scales of loudness, brightness, pitch, color, and temperature. This makes it possible both to assess the quantitative rules that show how components of metaphorical and literal meanings combine, and to trace the development of these rules from childhood to adulthood. This research will also evaluate the relation between comprehension of synesthetic metaphor (a psycholinguistic task) and cross-modality matching (a sensory-perceptual task). Children who served in the metaphor experiments will also be asked to match sensation intensities of different modalities (brightness and loudness), in order to determine whether the ability to interpret synesthetic metaphors is related to the ability to make systematic cross-modality matches and to determine whether experience making such matches affects subsequent performance scaling the meanings of synesthetic metaphors.